CN1605188A

CN1605188A - Sheet transport apparatus and image reading apparatus

Info

Publication number: CN1605188A
Application number: CNA028252071A
Authority: CN
Inventors: 牧野裕一; 平山泰也
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2001-12-21
Filing date: 2002-12-18
Publication date: 2005-04-06
Anticipated expiration: 2022-12-18
Also published as: WO2003055199A1; EP1457036B1; CN1323539C; KR100732594B1; EP1457036A4; TWI231138B; US20040246540A1; TW200301650A; KR20040077680A; DE60233676D1; US7385735B2; EP1457036A1

Abstract

An image reading apparatus including: a supply device for supplying sheets to a reading position, a platen glass plate in the reading position, a platen roller opposed to the platen glass plate, a reading device for exposing a sheet on the platen glass plate to read an image on the sheet, and a white guide member upstream of the platen roller in the transporting direction, wherein a portion of the guide member closest to the platen roller is on the platen roller side with respect to a plane which includes the point in the outer periphery of the platen roller closest to the platen glass plate and which is parallel to the platen glass plate, and wherein the longitudinal length of the guide member is the same as or larger than the width of the range of the reading device.

Description

Sheet transport apparatus and image reading apparatus

Technical field

Paper will wherein be supplied with and transport to the image reading apparatus that the present invention relates to be used in the sheet transport apparatus in photocopier, scanner, the facsimile machine etc. and have described sheet transport apparatus when the image on the paper will be read out.

Background technology

Up to now, all be equipped with and open enclosed original paper treatment facility but be located at some image reading apparatus in digital copier, printer, the facsimile machine etc., but the described enclosed original paper treatment facility of opening is the example that is used for automatically supplying with to described image reading apparatus the sheet transport apparatus of form original paper such as paper.Described image reading apparatus is read by the exposure device carries out image on the automatic original paper of supplying with of described original paper treatment facility.

Conventional example as exposure device, a kind of image reading method (be referred to as hereinafter to flow and read) is known, according to described method, exposure device is fixed on the predetermined read-out position place on the pressuring plate glass plate that is located in the image reading apparatus, reads image by making original paper move past described read-out position under predetermined speed.The favourable part of reading that should flow is that an original paper can promptly be changed by another original paper, and is applicable to multiple product.

Yet, in the described original paper treatment facility that utilizes the sensing technique that flows, wherein when being transported, read original paper, therefore original paper may projection or vertically vibrations under the influence of guider load or guider bending in readout.Therefore, original paper may rather unstable.

As the example of the method that addresses this is that, can use a kind of like this structure, wherein platen roller is arranged on pressuring plate glass plate opposite position so that original paper is pressed on the pressuring plate glass plate.

Figure 15 shows the example of traditional images readout equipment.Image reading apparatus shown in Figure 15 is equipped with: be used for the original glass stand 300 of read-out system (being referred to as the specification read-out system hereinafter), arrange that wherein fixedly original paper thereon is read out; The mobile glass 301 of reading that is used for mobile read-out system; And the pickup 302 that constitutes by contact image sensor etc., described pickup 302 is the image reading apparatus that are used for above two read-out systems.

In described mobile read-out system, to read that glass 301 is spaced a predetermined distance to be arranged in the described platen roller 304 of reading glass 301 tops that flows and to rotate with flowing under predetermined speed, thereby when flowing reading, original paper is transported with stable manner, has limited described original paper simultaneously from mobile amount of reading the upper surface projection of glass 301.

Use the described mobile read-out system of platen roller 304 to have such problem, that is, when in read-out position, having variation, that is to say, when pickup 302 exist to change in respect to the stop position of platen roller, may cause the variation in the intensity level of the image of reading.Figure 16 is the schematic diagram that is used to explain the traditional images readout equipment of the reason that this phenomenon occurs.

In Figure 16, the light path line that comes from lighting device 305 in the example of specification read-out system is represented that by Reference numeral 16A the light path line that comes from lighting device 305 in the example of read-out system that flows is represented by Reference numeral 16B.In Figure 16, the light path line that is fed to from lighting device on the side and transmits by original paper is schematically shown by double dotted line.In the example that illustrates, the read-out position that is used for mobile read-out system is offset to upstream side about the original paper direction of transfer from the position under platen roller 304 centers.

In the example of the specification read-out system of in Figure 16, representing by Reference numeral 16A, light by original paper 306 transmission along the direction of pickup 302 by white pressure plare 307 reflections, and the back of the body surface of irradiation original paper, described white pressure plare 307 is pressed in original paper 306 on the original glass stand 300.On the contrary, in the example of the mobile read-out system of being represented by Reference numeral 16B in Figure 16, because the bending of platen roller 304, a part of light that transmits and reflected by white platen roller 304 by original paper 306 is reflected away from pickup 302.

Therefore, reduce the luminous flux on the back of the body surface of irradiation original paper 306, caused the reduction in brightness when scioptics 308 are read reflection ray in the original paper by imageing sensor 309.Because read-out position removes from the position under platen roller 304 centers, therefore reduced along pickup 302 light flux reflected, caused even the further reduction of image brightness when reading same original paper.The light transmittance of original paper 306 is high more, and the influence of this phenomenon is just big more.Therefore, original paper 306 is thin more, and the reduction of brightness aspect is just obvious more.

For carries out image under the situation about influencing in this kind reduction that is not subjected to aspect the brightness is read, pickup 302 accurately must be arranged in platen roller 304 centers of rotation under the position, wherein can obtain essentially identical brightness in the example with the specification read-out system.

Yet,, be difficult with respect to the accurate location on the platen roller 304 execution pickups 302 because pickup 302 operation or stop to wait being mounted to such an extent that allow accuracy in the stop position of hinge fraction of the ADF303 that opens and closes.

In addition, platen roller 304 centers under the part on mobile surface of reading glass 301 and the adhesion that its part on the downstream on the original paper direction of transfer all is subjected to dust.When having dust at the read-out position place, image will have striped.Consider this point, expectation is arranged on read-out position with respect to the upstream end slightly under platen roller 304 centers.

In order to prevent owing to the dust of reading on the glass 301 that flows produces streak image, a kind of like this method has been proposed, according to this method, when making that platen roller 304 rotates, read in the read-out position place carries out image of reading that is used for flowing, wherein original paper is not transmitted, thus mobile dust and the platen roller 304 lip-deep dusts of reading on the glass 301 of difference.When read when detecting dust on the glass 301 flowing, make read-out position move.Carry out the example of the operation be used for preventing that streak image from producing therein, the read-out position of reading that is used for flowing moves inevitably.

Aforesaid, because the influence of parts accuracy and be used to the operation that prevents that streak image from producing, be difficult to make the read-out position of reading that flows to keep identical with respect to platen roller 304 always.Therefore, can cause the variation aspect brightness as mentioned above.

Figure 17 shows another example of the part-structure of the original paper treatment facility that is positioned near the use platen roller of read-out position.Near the read-out position of this legacy equipment that uses platen roller, the transport roller that provides on the upstream side that is arranged on read-out position 401 and the downstream and be suitable for transportation original paper under predetermined speed is to 402 and 403, and is substantially disposed in the platen roller 405 that read-out position top and drive unit (not shown) can make it to rotate.

Exposure device 409 is set at the following of pressuring plate glass plate 404 so that carries out image read operation on the original paper that at the uniform velocity transports between platen roller 405 and the pressuring plate glass plate 404.In order to make the luminous flux on exposure device between reading duration 409 stable, thereby prevent to have an X-rayed phenomenon, and realize that when original paper transparent reading in the example of thin paper or lining paper (intermediate paper) contrast on character and the background strengthens, the color of platen roller 405 is white.Like this, wherein the scope of being read by exposure device 409 may one be decided to be the scope that the whiteness of platen roller 405 wherein is suitable for reading.Consider this point, this exposure device be arranged on usually platen roller under.

In addition, platen roller 405 is supported by shaker arm 406 so that can be about fulcrum shaft 407 (in the present embodiment, described fulcrum shaft 407 is also as the axle of transport roller to a roller in 402) vibration, and platen roller 405 is pushed element 408 and suppresses downwards.Because this layout, when the original paper treatment facility was closed, shaker arm 406 was resisted against on the pressuring plate glass plate 404 and by equalization and follows read-out position 401.

If this moment platen roller 405 with pressuring plate glass plate 404 contacted words, it is friction twitch-up glass plate 404 consistently, thereby damages glass.Consider this point, make the external diameter of shaker arm 406, between pressuring plate glass plate 404 and platen roller 405, form gap X greater than the external diameter of platen roller 405.

By making this gap X minimize, can prevent the projection of original paper in the transportation so that under the appropriate brightness level, carry out image and read.At this moment, platen roller 405 is driven, so that can not transmit original paper under original paper applies the situation of any load.Particularly, contact image sensor is used for the situation of exposure device 409 therein, and it is less to read the degree of depth, and therefore employed in many cases platen roller 405 all is easily to make the minimized platen roller 405 of gap X.

There is following problem in the traditional original paper treatment facility that uses platen roller 405 execution flows to read: in order to stablize between reading duration the luminous flux on the exposure device to prevent to have an X-rayed phenomenon, and in order to realize that when exposing the contrast on character and the background strengthens, and is provided with the white element in the face of the back of the body surface of original paper in the part of the image reading apparatus on the sidepiece relative with read-out position for transparent original paper in the example of thin paper or lining paper.In this, use the original paper treatment facility of platen roller not make an exception, and the white platen roller relative with read-out position is housed usually.

In using the structure of platen roller, because the bending of platen roller, if read-out position departs from the position under the platen roller, the distance between read-out position and the roller has increased, and causes not enough luminous flux.This also can cause the shade in the gap between platen roller and near the guider it to be reflected, thereby causes the result of the whiteness degeneration of background, wherein is that background rather than black are read out.

In not having the position of the problems referred to above, carry out the limitation of reading in the scope that to cause wherein in the situation of the original paper treatment facility that uses platen roller, allowing to read.Similarly, when use its read the degree of depth less than CCD read the hookup image sensor (CIS) of the degree of depth time, the influence of the bending of platen roller will bigger, this means that the scope that wherein allows to read is limited near the part place, position under the platen roller.

Consider this point, by convention, read-out position has been adjusted to such position,, can carry out suitable reading by using anchor clamps, checkout gear etc. to carry out the position adjustments of platen roller and exposure device in this position that is.

By making the diameter of white roller make gentler also can the widening of flexibility read the zone greatly as much as possible.Yet the component change of given original paper treatment facility and the component change of exposure device must be used to have larger-diameter white platen roller, thereby cause the increase of equipment size and the increase of cost.

Summary of the invention

The present invention has been proposed in order to address the above problem.Therefore an object of the present invention is to provide a kind of image reading apparatus and image forming apparatus, read even described image reading apparatus also can be carried out the stable image that comprises the variation of image brightness aspect hardly when having variation aspect read-out position with described image reading apparatus.

Another object of the present invention is to increase wherein exposure device under the situation that white roller diameter increases and can carry out the scope of reading reliably not relating to.

To achieve these goals, according to illustrative structure of the present invention, allow to read the image reading apparatus of original paper during at the original paper conveying arrangement that the original paper that is used for the transporting sheets form is housed and at the transportation original paper, image reading apparatus comprises: the transparent element that is used for original paper is supported on the image read-out position; Be arranged in the position relative and be suitable for the read-out device of from the lighting device original paper on transparent element supply light with the image of reading original paper with transparent element; And it is relative with transparent element and be set at rotating rotating element in the position on the side relative with lighting device and read-out device.In addition, near cremasteric reflex element rotating element, the light that reflection is launched from lighting device when being used for reading original paper in the transportation original paper.

In addition, to achieve these goals, according to illustrative structure of the present invention, sheet transport apparatus comprises: the feeding mechanism that is used for plurality of sheets of paper is fed to continuously predetermined read-out position; Be located at the pressuring plate glass plate in the predetermined read-out position; The platen roller relative with the pressuring plate glass plate; Relative and be suitable on the paper on the pressuring plate glass plate carrying out exposure with the pressuring plate glass plate on being positioned at the platen roller opposite flank to read the read-out device of the image on the paper; And along transporting direction and the relative white guide element of pressuring plate glass plate on the platen roller upstream side; In addition, in this equipment, wherein the guide element position that is close to platen roller most is positioned on the platen roller side with respect to such plane, described plane comprises the point in the platen roller excircle that is close to the pressuring plate glass plate most and is parallel to the pressuring plate glass plate, and the longitudinal length of guide element is identical or longer than described width with the width of the scope of the read-out device that allows to read.

Description of drawings

Fig. 1 shows the schematic diagram of original paper treatment facility and image reading apparatus;

Fig. 2 is the sectional view of original paper treatment facility;

Fig. 3 shows the sectional view of the part around the read-out position;

Fig. 4 shows the view of the position relation between white guide element and the platen roller;

Fig. 5 shows the view of the position relation between white guide element and the platen roller;

Fig. 6 shows the view of the position relation between white guide element and the platen roller;

Fig. 7 is the mobile detailed sectional view of reading part of the related image reading apparatus of third embodiment of the invention;

Fig. 8 is the sectional view of the image reading apparatus of third embodiment of the invention;

Fig. 9 shows the schematic diagram that prevents brightness variation effect of the image reading apparatus of third embodiment of the invention;

Figure 10 shows the chart of the relation between the brightness of white background of read-out position in mobile the reading in the image reading apparatus of third embodiment of the invention and original paper;

Figure 11 shows the chart of the relation between the brightness of white background of the read-out position that flows when white paper element is not provided in reading and original paper;

Figure 12 is the mobile detailed sectional view of reading part of the related image reading apparatus of fourth embodiment of the invention;

Figure 13 shows the schematic diagram that prevents brightness variation effect of the related image reading apparatus of fourth embodiment of the invention;

Figure 14 is the sectional view of the related image forming of fifth embodiment of the invention;

Figure 15 is the sectional view of traditional images readout equipment;

Figure 16 shows that the variation in the brightness is the schematic diagram how to produce in the traditional images readout equipment; And

Figure 17 shows near the schematic diagram of the part-structure of the traditional original paper treatment facility the read-out position.

Carry out optimal mode of the present invention

(first embodiment)

Fig. 1 shows the schematic diagram of original paper treatment facility and image reading apparatus.In this example, be to use a kind of equipment of the read-out system that flows as the original paper treatment facility of sheet transport apparatus example.Original paper treatment facility 101 is arranged on the top of image reading apparatus 102 by hinge fraction 104.It is transported to a pile original paper on the original paper dish read-out position " e " of image reading apparatus 102 one by one.

The exposure device 103 that image reading apparatus 102 has pressuring plate glass plate 10, ramp 11 and is used as read-out device.Between the delivery period, exposure device 103 is fixed in the read-out position " e " at original paper, and carries out mobile the reading on the image of the original paper betransported under predetermined speed.

Next, describe the single face original paper with reference to Fig. 2 and how to betransported, wherein Fig. 2 is the sectional view of the original paper treatment facility 101 of present embodiment.

Original paper is piled up part A and is comprised feed table 1, is stacking original paper in its surface.

Original paper transport section B has pick-up roller 2, the original paper that described pick-up roller 2 will be deposited on the feed table 1 extracts in the separating part 3 (3a, 3b), and with friction separating pad 3b original paper is piled uppermost one by feed roller 3a and separate and be transported to tube roll 4 (4a, 4b).

When the leading edge of original paper arrives tube roll 4 (4a, 4b) when locating, during tube roll 4 (4a, 4b) remains static.They form ring to proofread and correct the crooked supply of original paper in by the original paper of feed roller 3a transportation, then original paper is transported to the upstream transport roller 5 (5a, 5b) as feeding mechanism.

Upstream transport roller 5 (5a, 5b) makes the original paper supplied with pass the gap between platen roller 6 and the pressuring plate glass plate 10 and transports described original paper towards downstream transport roller 7 (7a, 7b).

During being used for that original paper is directed to these a series of transport operation of downstream transport roller 7 (7a, 7b) from upstream transport roller 5 (5a, 5b), the original paper that is clamped by upstream transport roller 5 (5a, 5b) and downstream transport roller 7 (7a, 7b) is being transported under the predetermined speed on the read-out position " e ", and the exposure device in the position below the read-out position " e " that is fixed on the pressuring plate glass plate 10 103 is carried out exposing operation, reads image by image reading apparatus 102.

The original paper that discharges from downstream transport roller 7 (7a, 7b) is directed into the conveying roller 8 (8a, 8b) of original paper transport section C.When carrying out exposing operation in read-out position " e ", conveying roller 8 (8a, 8b) is separated from each other and does not carry out transport operation among the original paper transport section C.Passed read-out position " e " and finish when reading at the trailing edge of original paper, conveying roller 8b moves up, and original paper is transferred roller 8a and conveying roller 8b clamps, and faces down to be transported to and carry on the transfer dish 9 of piling up part D.

Next, will a kind of method of the transportation of the related two-sided original paper of present embodiment be described.At first, will be deposited in original paper by original paper transport section B piles up original paper on the part A and is transported to one by one on the read-out position " e " on the pressuring plate glass plate 10.

With the same in the example of single face original paper transportation, the original paper that passes through on read-out position " e " is by upstream transport roller 5 (5a, 5b) and downstream transport roller 7 (7a, 7b) clamping, and betransported between pressuring plate glass plate 10 and platen roller 6 under predetermined speed.At this moment, with the same in the example of single face original paper, exposure device 103 is fixed in the position below the read-out position " e " and the image of first side in the document image readout equipment.

In original paper transport section C, after the trailing edge of original paper has passed feeding sensor S1, conveying roller 8 (8a, 8b) commutation, and the tube roll 4 (4a, 4b) that original paper was inverted and was transported to the original paper transport section B that is positioned on the side opposite with throughput direction is located.

The read-out position " e " that tube roll 4 (4a, 4b) is transported to original paper on the pressuring plate glass plate 10 is once more located, and with the same in the example of first side, by upstream transport roller 5 (5a, 5b) and downstream transport roller 7 (7a, 7b) at transportation original paper under the predetermined speed so that on second side, carry out exposing operation before original paper being directed to original paper transport section C place.

In original paper transport section C, because the structure of the original paper treatment facility 101 of present embodiment, if original paper is transferred according to former state after second side is read, the original paper of being carried is just piled up in supine mode, thereby causes the order of original paper mistake to occur.Therefore, in order to proofread and correct the order of original paper, original paper once more must reverse.Consider this point, in original paper transport section C, after the trailing edge of original paper has passed feeding sensor S1, make conveying roller 8 (8a, 8b) commutation so that once more along the direction transportation original paper of tube roll 4 (4a, 4b), the counter-rotating original paper is so that be transported on the transfer dish 9 of carrying accumulation part D in ventricumbent mode.

Next, Fig. 3 shows the sectional view of the part around the read-out position of image reading apparatus of present embodiment.With reference to Fig. 3, will the structure of the platen roller 6 of present embodiment be described.Reading in the part of the original paper treatment facility 101 of present embodiment, upstream transport roller 5 (5a, 5b) is arranged on the upstream side of read-out position " e ", and downstream transport roller 7 (7a, 7b) is arranged on the downstream of read-out position " e ".Platen roller 6 is arranged on the top of read-out position " e " substantially, and is supported by a pair of shaker arm 13 at its place, two ends, so the drive unit (not shown) can make its rotation.

The position of exposure device 103 under read-out position remains static, and wherein carries out reading of the original paper that transports in described read-out position.And one axle in shaker arm 13 and the upstream transport roller 5 (5a, 5b) is connected, and uses described axle can make shaker arm 13 vibrations as the vibration fulcrum.And shaker arm 13 receives the downward force of pushing member 14.Therein in the situation that original paper treatment facility 101 is opened, use vibration fulcrum as the centre of oscillation to make shaker arm 13 equalizations, wherein platen roller 6 is fully depressed.In the original paper treatment facility 101 pent situations, shaker arm 13 is followed pressuring plate glass plate 10 and by equalization, is received basic directly downward power simultaneously therein, and wherein platen roller 6 is in the top of read-out position " e " substantially.

And the external diameter of shaker arm 13 is slightly greater than the external diameter of platen roller 6, and shaker arm 13 contacts with pressuring plate glass plate 10, thereby forms minim gap between platen roller 6 and pressuring plate glass plate 10.

Because the formation of this minim gap is not if platen roller 6 rotation pressuring plate glass plates 10 can be damaged when having paper.And best is not transport original paper suitably reading under the degree of depth of exposure device 103 under original paper applies the situation of load.

Next, Fig. 4 and Fig. 5 show the relation of the position between the white guide element and platen roller in the present embodiment.With reference to Fig. 4 and Fig. 5, will the structure of guide element be described.Guide element 12 is to use the flexible white films that is made of polyester film to make, and has flat structures as shown in Figure 5.

It is how to arrange with respect to transporting direction that Fig. 4 shows guide element 12.Guide element 12 is fixed in the far-end of the transportation guider 20 that is made of resin or metal.The far-end of guide element 12 is freely.Yet aforesaid, platen roller 6 is designed to be equalization, so that original paper treatment facility 101 is closed with respect to image reading apparatus 102 in this state, makes that wherein the platen roller 6 of following pressuring plate glass plate 10 is disposed in the pre-position.In the following description, platen roller 6 is in this position relation.

Position between guide element 12 and the platen roller 6 relation is as described below: wherein guide element 12 position that is close to platen roller 6 most is positioned on the platen roller side with respect to plane β, and described plane β is parallel to the pressuring plate glass plate and comprises point in platen roller 6 excircles that are close to pressuring plate glass plate 10 most.

That is to say that in the present embodiment, guide element 12 is close to platen roller 6 most along the far-end of transporting direction, this far-end is positioned on the β of plane.Thereby adopting this layout is to wipe the imaging surface of original paper for the far-end that prevents guide element 12 in the original paper transportation contacts with original paper, thereby and in order to prevent that load is applied in original paper and produces blurred picture.

In addition, as shown in Figure 5, the width Y1 of guide element 12 is identical or longer than described width Y2 with the width Y2 of the scope " f " of the exposure device 103 that allows image to read, thereby prevents the intrusion of ambient light between the image reading duration and the reflection of parts shade.

Because said structure, even because the variation in original paper treatment facility 101 and the image reading apparatus 102, the variation in platen roller 6 substrates etc. cause read-out position to depart from position under the platen roller 6, luminous flux around the platen roller can be bigger, therefore the influence of the shade that is produced between guider and the roller and because influence that the luminous flux aspect that bending caused lacks has been alleviated allows the scope of reading thereby increased exposure device.

And flexible by using, thin tunica albuginea can be filled near the gap platen roller as guide element, thereby the effect that more strengthens is provided.Therefore and guide element can not contact with original paper, can scrub images or apply load to it.

(second embodiment)

Next, describe second embodiment of the original paper treatment facility of the mobile read-out system of use of the present invention with reference to the accompanying drawings, described original paper treatment facility is the example of sheet transport apparatus.Represent with identical Reference numeral with those identical among first embodiment parts, and will omit description it.

Guide element 12 is to use the flexible white films that is made of polyester film etc. to make, and has flat structures as shown in Figure 5.It is how to arrange with respect to transporting direction that Fig. 6 shows guide element 12.As shown in Figure 6, an end of guide element 12 is bonded on the transportation guider surface on original paper treatment facility 101 inboards, and its other end contacts with platen roller.

As described with reference to first embodiment, this moment, platen roller 6 was designed to be equalization, so that shown in state in, original paper treatment facility 101 is closed with respect to image reading apparatus 102, and platen roller 6 is followed pressuring plate glass plate 10 so that be disposed in the pre-position.In the following description, platen roller 6 is in this position relation.

Position between guide element 12 and the platen roller 6 relation is as described below: wherein guide element 12 is resisted against position on the platen roller 6 and is positioned on the platen roller side with respect to plane β, and described plane β is parallel to the pressuring plate glass plate and comprises point in platen roller 6 excircles that are close to pressuring plate glass plate 10 most.That is to say that in the present embodiment, guide element is close to platen roller 6 most with respect to the far-end of transporting direction, only need make this far-end be positioned at plane β and upward and with platen roller contact.

Thereby adopting this layout is to wipe the imaging surface of original paper for the far-end that prevents guide element 12 in the original paper transportation contacts with original paper, thereby and in order to prevent that far-end applies load generation blurred picture to imaging surface in the original paper transportation.

And, guide element 12 is promoted along direction γ consistently by the elastic force of himself, even and bonding error when bonding of its position, the variation in the platen roller 6 etc. depart from, it follows platen roller 6, so that positional precision is easy to realize, and guarantee between the far-end of relation between pressuring plate glass plate 10 and the guide element 12 and platen roller 6 and guide element 12 against relation, make to keep above-mentioned state.

In addition, as shown in Figure 5, the width Y1 of guide element 12 is identical or bigger than described width Y2 with the width Y2 of the scope " f " of the exposure device 103 that allows image to read, thereby can prevent the intrusion of ambient light between the image reading duration and the reflection of parts shade.

And, because wherein the flexible thin white films contacts with platen roller consistently and follows the structure of platen roller, guide element can cover near the part the position under the platen roller under situation about not being projected in the transportation route, thus with first embodiment in compare and can further increase the scope of reading of allowing.

Particularly, under this structure, read range can be set to such an extent that can cover the guide element that comprises roller segment, thereby also can guarantee wide read range even use it to read the less hookup image sensor (CIS) of the degree of depth.

Aforesaid, according to the present invention, wherein on the end position that white guide element under the pent state of original paper treatment facility is close to platen roller most is positioned at platen roller side with respect to such plane, described plane parallel is in pressuring plate glass plate 10 and comprise point in the platen roller excircle that is close to pressuring plate glass plate 10 most, and the longitudinal length of guide element is identical or longer than described length with the length of the scope of the exposure device that allows to read, even thereby read-out position departs from the position under the platen roller 6, luminous flux around the platen roller can be bigger, therefore the influence of the shade that is produced between guider and the roller and because the influence that the luminous flux aspect that bending caused lacks has been alleviated allows the scope of reading thereby can increase exposure device.

And the end of guide element is not projected in the transportation route, therefore can not contact with original paper so that swipe original paper or generation blurred picture.In addition, in the guide element structure of second embodiment, guide element so is provided, that is, make it under the elastic force of himself, be pushed to platen roller, thereby even in the position of platen roller, have variation, it also follows platen roller always, but thereby the holding position precision, and it can not be projected in the transportation route or leave platen roller, thus can cover near the part position under the roller.

Because this layout, not only can read on the platen roller but also can on guide element, read, even therefore use it to read the degree of depth little exposure device as in the CIS example, also can guarantee enough big read range.And, owing to allow to read on a large scale, just need not to regulate read-out position.In addition,, just need not to use large diameter platen roller, thereby realize the reduction in equipment size and the cost owing to allow to read on a large scale.

(the 3rd embodiment)

Though the present invention is applicable to the discrete picture readout equipment in the above-described embodiments, should not think that this is restrictive.Also can be with the image reading apparatus of above-mentioned image reading apparatus as image forming apparatus with the image processing system that comprises the image supporting member and act on the device on the image supporting member.

Below, the fourth embodiment of the present invention is described with reference to the accompanying drawings.

(the 4th embodiment)

To Figure 11 the related image reading apparatus of fourth embodiment of the invention is described with reference to Fig. 7.General section view, Fig. 9 that Fig. 7 is image reading apparatus the mobile detailed sectional view of reading part, Fig. 8 is image reading apparatus shows the chart of the relation between the brightness of white background that the schematic diagram that prevents brightness variation effect of reflecting element and Figure 10 and Figure 11 show the read-out position that flows in reading and original paper.

{ general structure of image reading apparatus }

As shown in Figure 8, the image reading apparatus E of present embodiment comprises that image reads part 201 and ADF202, and described ADF202 is mounted in image and reads automatic original paper transporting equipment on part 201 tops.

Image is read part 201 can read original paper in book read-out system and the mobile read-out system.That is to say that original glass stand 203 is arranged on image and reads on the upper surface of part 201, and, at an end place of original glass stand 203, be provided with the mobile glass plate 204 of reading as transparent element, be used to support and will read the original paper that is read out by flowing.

And, below glass plate, be provided with owing to read the read-out device 205 of the image of original paper.This read-out device 205 comprises housing 209, and described housing 209 is integrally contained: be used for the original paper supply light on glass plate lighting device 206 (such as the xenon pipe), be used for making the SELFOC lens 207 of the reverberation imaging that comes from original paper and the contact image sensor 208 that is arranged in the image space of SELFOC lens 207.Make housing 209 be resisted against original glass stand 203 or flow by adjacent element (not shown) and read on the glass plate 204, and make that read-out device 205 and original paper surface are spaced a predetermined distance from high sliding.

ADF202 is installed in image and reads the top of part 201 so that can be by opening and closing such as hinges, and provide: roller 211a is to 211f, and described roller 211a is suitable for that to 211f original paper is fed to image and reads part 201 and be deposited in the original paper conveying arrangement that original paper is piled up the original paper of the paper form on the part 210 as transporting in mode one by one; As the platen roller 212 of rotating element, the readout original paper that is used for preventing flowing is read projection on the glass plate 204 from flowing; And original paper transport portion 213, be used to carry and experienced the original paper that image is read.

In the example of book read-out system, be arranged in the white pressure plare 214 that the original paper on the original glass stand 203 is installed on the ADF202 and be fixed in the position, and original paper is read out when driving read-out device 205 along time scanning direction (horizontal direction among Fig. 8) under predetermined speed.When book was read, ADF202 was as the pressure plare that original paper is fixed in original glass stand 203.

In the example of read-out system that flows, the original paper that the original paper that is deposited in ADF202 is piled up on the part 210 is transported to position below the platen roller 212 by feed roller 211a supply and by transport roller 211b, 211c and 211d under predetermined speed.Original paper is limited in such amount, promptly, under described amount, the platen roller 212 that rotates under predetermined velocity of rotation can rise its upper surface of reading glass plate 204 from flowing, and be fed on the original paper that is transported between platen roller 212 and the mobile upper surface of reading glass plate 204 in the light that the read-out device 205 of inactive state will come from lighting device 206 at predetermined read-out position, thereby carries out image is read everywhere.Original paper by platen roller 212 is directed to transport roller 211e and 211f by ramp 215 and is transported on the original paper transport portion 213.

{ being used between mobile reading duration, preventing the layout that brightness changes }

Next, use description between mobile reading duration, prevent the layout that brightness changes.As shown in Figure 7, the ADF202 of present embodiment is equipped with white flex plate element 216, as the reflecting element that is arranged in along the original paper transporting direction on platen roller 212 upstream sides.This white panel element 216 is installed in the guide element 240 that is used for towards platen roller 212 guiding original papers to be basically parallel to the mode of reading glass plate 204 that flows.White panel element 216 with flow read distance C 2 between the glass plate 204 read greater than flowing between glass plate 204 and platen roller 212 surfaces distance C 1 and less than (C1＜the C2＜C1+R) of the distance (C1+R) between the mobile center of rotation of reading glass plate 204 and platen roller 212.

And, so definite wherein panel element 216 is close to the end position 217 of platen roller 212, promptly, when the direction (reading direction) along rotating element is seen past tense from the read-out position that is used for read-out device 205, promptly, when past tense is seen in the position of reading from flowing along platen roller 212 and the direction of arranging white panel element 216 thereon under the glass plate 204, the part of platen roller 212 is hidden in substantially along on the entire image read range of the main scanning direction of read-out device 205 (platen roller 212 vertically).In addition, the read-out position in the example of mobile read-out system is set to the position of reading that allows platen roller 212 surfaces when not having original paper to betransported.

The brightness minimizing effect that prevents of the white panel element 216 of present embodiment can schematically be described with reference to Fig. 9.Fig. 9 schematically shows from lighting device 206 and is applied to that a side (left-hand side this embodiment) goes up and the route of light by the original paper transmission.The read-out position read of flowing is set to along the original paper transporting direction from platen roller position deviation under 212 the center of rotation to the position of upstream side.

Light by original paper 218 transmission is reflected by the direction of white panel element 216 along read-out device 205.What can find out is that the luminous flux that puts on original paper 218 back of the body surfaces is greater than the situation in the conventional example of being represented by Reference numeral 16B among Figure 16.Since this layout, the minimizing in the time of can alleviating the position under read-out position departs from platen roller 212 centers in the brightness.

Figure 10 and Figure 11 show the measurement result (0 to 255 grade) that concerns between the brightness of white background of the read-out position that flows in reading and original paper.Figure 10 shows the measurement result of the present embodiment that white panel element 216 wherein is installed, and Figure 11 shows the measurement result that the example of white panel element 216 wherein is not installed.

As shown in Figure 11, when white panel element 216 is not provided, when read-out position depart from platen roller 212 centers of rotation under the position time original paper the brightness of white background reduce widely.In contrast, as shown in Figure 10, when with present embodiment in the same when white panel element 216 is provided, the minimizing of brightness aspect is slight, even change aspect read-out position, the variation in the brightness also can be maintained at no problem substantially level.

Since wherein white panel element 216 with flow read distance C 2 between the glass plate 204 read greater than flowing between glass plate 204 and platen roller 212 surfaces distance C 1 and less than the such layout of distance (C1+R) between the mobile center of rotation of reading glass plate 204 and platen roller 212, white panel element 216 can not contact with the original paper 218 of compression plate roller 212 control, and white panel element 216 is under the situation that does not hinder original paper 218 transportations or do not swiping the original paper surface and produce the light that reflection under the situation of dust comes from lighting device 206.

In addition, in the present embodiment, when from the read-out position of read-out device 205 upwards (along the direction of platen roller 212) see past tense, white panel element 216 is hidden in the part of platen roller 212 on the whole read range, and therefore that apply from read-out position by lighting device 206 and light by the original paper transmission is reflected reliably by white panel element 216 or platen roller 212.Therefore, the reduction of brightness aspect can not appear.

And, because white panel element 216 is mounted to be parallel to the mode of reading glass plate 204 that flows, therefore the light that is transmitted by original paper with the example of light by white pressure plare 214 reflections during book is read in identical mode be reflected, and book read with mobile reading between do not have big-difference aspect the brightness.

And, the read-out position read of flowing be set to platen roller 212 center of rotation under the position and the position between the far-end 217 of white panel element 216.That is to say, when not having original paper to betransported, it is set to the position that the surface of platen roller 212 wherein is read out, therefore carrying out that can distinguishing when detecting flows and read dust on the glass plate 204 and the dust on the platen roller 212, read thereby can carry out the high-quality image that does not comprise streak image.In addition, on the upstream side of the center of rotation by read-out position being set in platen roller 212 with respect to the original paper transporting direction, can make platen roller 212 stand the adhesion of dust less.

(the 5th embodiment)

Next, the 5th embodiment of image reading apparatus of the present invention is described with reference to Figure 12 and Figure 13.Figure 12 flows to read the detailed sectional view of part; Figure 13 shows the schematic diagram that prevents brightness variation effect.

Present embodiment is different from the 4th embodiment part and is, in the 4th embodiment, white panel element 216 is to be mounted to be parallel to the mode of reading glass plate 204 that flows, and the white panel element 216 in the present embodiment is thus arranged, promptly, when white panel element 216 during, make the white panel element 216 and the distance of reading between the glass plate 204 that flows increase near platen roller 212.As for other structures, this embodiment is identical with the structure of first embodiment.

That is to say, as shown in Figure 12, white panel element 216 installed on the bias so that white panel element 216 and mobile distance of reading between the glass plate 204 can be such, that is, and along the distance C 4 of the downstream end of original paper transporting direction distance C 3 greater than the upstream extremity place.Therefore, white panel element 216 is read minimum range C3 between the glass plate 204 and reads distance C 1 between glass plate 204 and platen roller 212 surfaces greater than flowing with flowing, and white panel element 216 and mobilely read ultimate range C4 between the glass plate 204 less than the distance (C1+R) between the mobile center of reading glass plate 204 and platen roller 212.

The brightness minimizing effect that prevents of the white panel element 216 of present embodiment is schematically described with reference to Figure 13 below.Figure 13 schematically shows from lighting device 206 and is transmitted on the side and the route of light by the original paper transmission.

Light by original paper 218 transmission is reflected by the direction of white panel element 216 along read-out device 205.The white panel element of present embodiment is read glass plate 204 and is tilted with respect to flowing, so it has the effect of assembling the light that transmits by original paper 218 along the direction of read-out device 205.Therefore, what can find out is, compares with the mobile example of reading part of first embodiment shown in Fig. 9, and more rays is launched from the dorsal part of original paper 218.Because this layout can further alleviate the minimizing in the brightness when read-out position departs from the center of rotation of platen roller 212, even and on read-out position, exist when changing, also can carry out the stable image that comprises the variation of brightness aspect hardly and read.

Except making that white panel element 216 tilts,, can more effectively will come from the light-ray condensing of lighting device 206 in read-out device 205 if make white panel element 216 constitute with respect to the shape of lighting device 206 with concave surface.

(the 6th embodiment)

Though the foregoing description is applicable to image reading apparatus, the present invention also is applicable to image forming apparatus G (such as photocopier), and as shown in Figure 14, integral body is formed with image reading apparatus E and image recorder F in described image forming apparatus G.

Figure 14 is the general illustration of image forming apparatus.The structure of image reading apparatus E is with identical in conjunction with the described structure of the 4th embodiment.The view data carries out image record that the view data that image recorder F is read according to image reading apparatus E or other image reading apparatus are read and carried.

Particularly, when image recording signal was transfused to, the recording medium that is contained among paper holding portion 219a, 219b, 219c and 219d and pallet 219e selected one was transported to and is used for the image processing system that image forms by driving selected of supplying with part 220a, 220b, 220c, 220d and 220e and transport roller 231.

Described image processing system comprises: photosensitive drums 221, be used for is the charger 222 of the surface charging of photosensitive drums 221 equably, be used on the surface of the photosensitive drums 221 that charger 222 is charged, optionally carrying out the exposure device 223 of exposure according to image information, be used for making that the exposure by exposure device 223 is formed on the latent electrostatic image developing on the photosensitive drums 221 and forms the developing apparatus 224 that will be transferred to the toner image on the recording medium that is transported, be used for photosensitive drums 221 lip-deep charge image developing toner images are transferred to transfer printing charger 225 on the recording medium, be used to separate toner image has been transferred to the recording medium on it from photosensitive drums 221 separating charger 226, and be used at the cleaner 227 of removing the residual toner on the photosensitive drums 221 after the toner image transfer printing.This image processing system forms image by electrophotography on recording medium.

Transport section 228 is transported to fixing device 229 with being formed with the record images media on it, and after heating with toner image recording medium is being sent on the transmission dish 230.

Image reading apparatus E by combination like this and image recorder F are to form image forming apparatus G, can prevent effectively that the brightness between the mobile reading duration of original paper from changing, same with the above-mentioned embodiment, can carry out stable image and read, and can realize that on this basis the high-speed image of high-quality forms.

(other embodiment)

Though contact image sensor is used to image reading apparatus in the above-described embodiments, also can uses refrative mirror and CCD, or be directed to the surface of photo-sensitive cell of image forming apparatus with the reverberation that refrative mirror will come from original paper so that directly exposure.

In the above-described embodiments, for fear of mobile effect of dust of reading on the glass plate 204, read-out position be set along the original paper transporting direction be positioned at platen roller 212 center of rotation under on the upstream side of position, and white panel element 216 is arranged on the upstream side.Yet, it should be noted that the shape by the original paper transportation route etc. also can change the adhesion of flowing and reading dust on the glass plate 204.Consider this point, also read-out position can be set along the original paper transporting direction be positioned at platen roller 212 center of rotation under on the downstream of position, therefore the white panel element 216 as reflecting element can be located on the downstream, maybe the read-out position that flows can be set be positioned at platen roller 212 center of rotation under on each side of position, on each side in upstream side and downstream, provide white panel element 216 along the original paper transporting direction.

Though the white panel element that is easy to reflection ray in addition in the above-described embodiments should not think that as reflecting element this is restrictive.Reflecting element can be any other type, as long as can reflect the light that comes from lighting device 206 effectively.

Aforesaid, according to the present invention, provide: the feeding mechanism that is used for plurality of sheets of paper is fed to continuously predetermined read-out position; Be located at the pressuring plate glass plate in the predetermined read-out position; Be set to the platen roller relative with the pressuring plate glass plate; Relative and be suitable on the paper on the pressuring plate glass plate carrying out exposure with the pressuring plate glass plate on being positioned at the platen roller opposite flank to read the read-out device of the image on the paper; And along transporting direction and the relative white guide element of pressuring plate glass plate on the platen roller upstream side; Wherein the guide element position that is close to platen roller most is positioned on the platen roller side with respect to such plane, described plane comprises the point in the platen roller excircle that is close to the pressuring plate glass plate most and is parallel to the pressuring plate glass plate, and wherein the longitudinal length of guide element is identical or bigger than described width with the width of the scope of the read-out device that allows to read, and carries out the scope of reading reliably thereby can increase exposure device under the situation that does not comprise increase aspect the white roller diameter.

Aforesaid, according to the present invention, provide the reflecting element that when transportation is read original paper during original paper, is used to reflect the light that comes from lighting device, therefore the light by the original paper transmission is reflected so that from the backside illuminated original paper along the direction of image reading apparatus.Therefore, comprise the stable image that the image brightness aspect changes hardly and read even aspect the read-out position that flows, exist also can carry out when changing.

Claims

1. sheet transport apparatus comprises:

Be used for plurality of sheets of paper is fed to continuously the feeding mechanism of predetermined read-out position;

Be located at the pressuring plate glass plate in the predetermined read-out position;

The platen roller relative with the pressuring plate glass plate;

Relative and be suitable on the paper on the pressuring plate glass plate carrying out exposure with the pressuring plate glass plate on being positioned at the platen roller opposite flank to read the read-out device of the image on the paper; And

Along transporting direction and the relative white guide element of pressuring plate glass plate on the platen roller upstream side;

It is characterized in that, the position that guide element is close to platen roller most is positioned on the platen roller side with respect to such plane, described plane comprises the point in the platen roller excircle that is close to the pressuring plate glass plate most and is parallel to the pressuring plate glass plate, and the longitudinal length of guide element is identical or longer than described width with the width of the scope of the read-out device that allows to read.

2. according to the sheet transport apparatus described in the claim 1, it is characterized in that, the far-end of described guide element contacts with platen roller with respect to the position of a plane on the platen roller side, and described plane comprises the point in the platen roller excircle that is close to the pressuring plate glass plate most and is parallel to the pressuring plate glass plate.

3. according to the sheet transport apparatus described in the claim 1, it is characterized in that described guide element comprises having flexible white flexible member.

4. image reading apparatus comprises:

Be used to supply with the original paper treatment facility of paper; And

Be used for transporting sheets when image is read so that read the paper conveying arrangement of the image on the paper,

It is characterized in that described paper conveying arrangement is the sheet transport apparatus described in any in the claim 1 to 3.

5. image reading apparatus, described image reading apparatus are equipped with the original paper conveying arrangement that is used for transporting sheets form original paper and can read original paper when the transportation original paper, and described equipment comprises:

Be used for original paper is supported on the transparent element of image read-out position;

Be arranged in the position relative and be suitable for the read-out device that from the lighting device original paper on transparent element provides the image of light to read original paper with transparent element; And

It is relative with transparent element and be set at rotating rotating element in the position on the side relative with lighting device and read-out device,

It is characterized in that near cremasteric reflex element rotating element, the light that reflection is launched from lighting device when being used for reading original paper in the transportation original paper.

6. according to the image reading apparatus described in the claim 5, it is characterized in that the distance between reflecting element and the transparent element is less than the distance between the center of rotation of transparent element and rotating element and greater than the distance between the surface of transparent element and rotating element.

7. according to the image reading apparatus described in the claim 5, it is characterized in that, the far-end that is close to most the reflecting element of rotating element is so arranged, promptly, make that reflecting element is hidden in the part of rotating element on the whole basically read range of read-out device when seeing past tense along the direction of rotating element from the read-out position of read-out device.

8. according to the image reading apparatus described in the claim 5, it is characterized in that reflecting element is positioned to and is parallel to transparent element.

9. according to the image reading apparatus described in the claim 5, it is characterized in that reflecting element is positioned to and makes when reflecting element distance increase between reflecting element and the transparent element during near rotating element.

10. according to the image reading apparatus described in the claim 5, it is characterized in that reflecting element comprises having flexible white plate.

11. the image reading apparatus according to described in the claim 5 is characterized in that, the read-out position that is used for reading during original paper in transportation original paper is set to such position, and wherein the surface of rotating element is read out when not having original paper to betransported.

12. the image reading apparatus according to described in the claim 11 is characterized in that, being used at the read-out position that original paper is read in transportation during original paper is upstream along the center of rotation of the rotating element of original paper transporting direction.

13. image forming apparatus, described image forming apparatus is equipped with the original paper conveying arrangement that is used for transporting sheets form original paper, and the information that image reading apparatus is read can be recorded on the recording medium, described image reading apparatus can be read original paper when the transportation original paper

Described image forming apparatus comprises:

Image reading apparatus described in the claim 5 to 12 any one; And

Be used for image is recorded in image processing system on the recording medium.

14. an image reading apparatus comprises:

Transparent panel;

Be used for original paper is transported to the transport roller of transparent panel;

With transparent panel relative to and be suitable for guiding described original paper so that the roller that original paper moves along transparent panel;

Be used to shine the lighting device of the original paper that moves along transparent panel;

Be used to read the imageing sensor of the image of the original paper that moves along transparent panel; And

Flexible leader, described flexible leader are disposed in the upstream of described roller and relative with transparent panel, and its free end is close to roller or contacts with roller,

It is characterized in that described flexible leader has the reflecting surface that is used to reflect the light that comes from lighting device.

15. the image reading apparatus according to described in the claim 14 is characterized in that, described guider is installed in the far-end that is used for original paper is directed to the transportation guider of transparent panel.

16. according to the image reading apparatus described in the claim 14, it is characterized in that, described imageing sensor is read the image of the part of mobile original paper, and external peripheral surface and the distance between the transparent panel that a described part is arranged in its central roll are the upstream of the position of minimum value.

17., comprise that also the image information that is used for reading according to imageing sensor forms the image processing system of image on recording medium according to the image reading apparatus described in the claim 14.